Morphologies and microstructures of tree-like carbon produced at different reaction conditions in a CVD process

Centimeter-size multi-branched tree-like carbon structures have been generated by the catalytic chemical vapor deposition of toluene using ferrocene as the catalyst precursor and investigated by means of SEM, TEM, and EDX. It is found that a temperature of 1000-1200 °C and a carrier gas flow rate of 1000-2500 ml/min are necessary for the generation of the carbon trees. Their morphologies and microstructures change greatly with the changing reaction conditions. The fractal dimensions of the trees are calculated to quantitatively investigate the influence of different reaction temperatures on the morphologies.     

酸增殖源及其在化学增幅抗蚀剂体系中的应用

介绍了酸增殖机理、酸增殖源的种类、典型化合物在化学增幅抗蚀剂体系中的应用及对灵敏度的提高 ,提出在计算机直接制版版材研究中的应用     

氧化铝上吸附平衡与动力学的分形特性

在实验测定氧化铝吸附氮气的平衡和动力学过程的基础上 ,由平衡数据得到分形维数 ,对动力学结果分别用欧氏几何和分形几何的动力学模型进行处理 ,比较两种方法得到的扩散系数之间的差别。结果表明 :粉状氧化铝的分形维数为 2 .12 ;采用分形动力学模型得到的扩散系数同欧氏几何扩散模型的结果不一样 ,扩散系数不随浓度的变化而改变 ;而欧氏几何扩散模型中的扩散系数随浓度变化发生改变 ,且变化符合Darken关系     

Stability analysis and controller design of interval type-2 fuzzy systems with time delay

The type-2 fuzzy models can handle the system uncertainties directly based on the type-2 fuzzy sets. In this paper, the Takagi–Sugeno fuzzy model approach is extended to the stability analysis and controller design for interval type-2 (IT2) fuzzy systems with time-varying delay. Delay-dependent robust stability criteria are developed in terms of linear matrix inequalities by using the improvement technique of free-weighting matrices. Less conservative results are obtained by considering the information contained in the footprint of uncertainty. Finally, two simulation examples are presented to illustrate the effectiveness of the theoretical results. One is provided to show the merits of the proposed method, the other based on the continuous stirred tank reactor model is given to illustrate the design processes of IT2 fuzzy controller for a nonlinear system with parameter uncertainties.     

高温浓硫酸液下泵的故障分析及处理

安徽铜都铜业股份有限公司金昌冶炼厂新建 300 kt／a铜冶炼烟气制酸装置干燥塔入口烟气温度(30±2)℃,烟气ψ(SO_2)9％±1％。干燥塔循环槽采用2台单级单吸离心立式悬臂液下泵,型号为LSB780-30B,一开一备。吸收塔循环槽液下泵型号也为LSB780-30B,为2台泵并联。     

A resilience optimization approach for workforce-inventory control dynamics under uncertainty

The presence of uncertainties in manufacturing systems and supply chains can cause undesirable behavior. Failure to account for these in the design phase can further impair the capability of systems to respond to changes effectively. In this work, we consider a dynamic workforce-inventory control problem wherein inventory planning, production releases, and workforce hiring decisions need to be made. The objective is to develop planning rules to achieve important requirements related to dynamic transient behavior when system parameters are imprecisely known. To this end, we propose a resilience optimization model for the problem and develop a novel local search procedure that combines the strengths of recent developments in robust optimization technology and small signal stability analysis of dynamic systems. A numerical case study of the problem demonstrates significant improvements of the proposed solution in controlling fluctuations and high variability found in the system’s inventory, work-in-process, and workforce levels. Overall, the proposed model is shown to be computationally efficient and effective in hedging against model uncertainties.     

Echo state networks based predictive model of vinyl chloride monomer convention velocity optimized by artificial fish swarm algorithm

Conversion rate in the Polyvinylchloride (PVC) polymerizing process has a certain influence on the molecular weight of PVC, porosity, absorption rate of plasticizer, vinyl chloride monomer (VCM) residue and thermal stability. Therefore, a predictive model based on echo state networks (ESN) method optimized by the artificial fish swarm algorithm (AFSA) is proposed to predict the conversion velocity. Firstly, the hot balancing mechanisms of polymerizer and the influenced factors of convention rate of VCM are analyzed in details. Then the auxiliary variables of the predictive model kernel are selected by using the kernel principal component analysis method for reducing the model dimensionality. Thirdly, the structure parameters of the ESN are optimized by the AFSA to realize the nonlinear mapping between input and output variables of the discussed soft-sensor model. The artificial fish swarm behaviors, such as foraging, swarming, chasing, random, are introduced in details. Finally, simulation results show that the proposed model can significantly enhance the predictive accuracy and robustness of the technical index and satisfy the real-time control requirements of PVC polymerizing production process.     

一种新的S/PDIF接收机数据译码的实现方法

论文分析了S/PDIF音频数据流的特点,引入模式识别中的训练机对S/PDIF音频数据流进行现场脉冲宽度特征提取。依据训练机结果建立分类器实现脉冲宽度分类,根据脉冲宽度进行同步前置码和逻辑电平的解码。利用硬件描述语言Verilog进行设计实现与验证,仿真结果说明这种特征提取方法可以提高S/PDIF接收机数据解译码的适应性和准确性。     

一种新的BOC(n,n)型信号的精确捕获算法

针对BOC(n,n)型信号自相关函数存在三个峰值导致伪码捕获模糊性的问题,提出了一种新的基于相关函数的精确无模糊的捕获算法。该算法将信号进行频域的多普勒补偿,通过本地增设QBOC(n,n)支路,利用BOC(n,n)信号自相关以及BOC(n,n)和QBOC(n,n)互相关,经移位±TC/4、取模、求和、平方运算而实现。理论与仿真分析表明,该算法在不改变自相关主峰宽度的情况下完全消除相关副峰的同时,显著提高了主峰峰值;比传统捕获算法的性能好4.5 dB左右,并且捕获精度良好、易于实现。